Can the assistants who help a Binding spell use a scroll?

[ksbsnowowl]

From the Binding spell in the PHB:

You may have as many as six assistants help you with the spell. For each assistant who casts suggestion, your caster level for this casting of binding increases by 1. For each assistant who casts dominate animal, dominate person, or dominate monster, your caster level for this casting of binding increases by a number equal to one-third of that assistant’s level, provided that the spell’s target is appropriate for a binding spell.

Suppose you were a 17th level enchanter, and were wanting to bind some outsiders.  You have some lower-level wizard or sorcerer assistants, but none of them can cast 9th level spells, thus none of them can cast Dominate Monster.

Could you craft a few scrolls of Dom Monster, and have your assistants cast it from the scrolls (making appropriate CL checks), each one adding +5 to your caster level (1/3 of 17th CL scroll, rounded down)?

Or do the assistants actually have to cast the spells under their own power?

[NunoM]

I'd say yes... A scroll is a spell completion item and the caster still has to provide the somatic and material components, so, technically, it's a cast. I would allow it.

EDIT: It's still, yes, for me, but the above reason is wrong.
Using a scroll is basically like casting a spell and is considered as such, for purposes of arcane spell failure chance (Scrolls).